Excess Content Research Articles

Role of binder on yield strength of polycaprolactone/dimethylsulfone composites for bio-applications

Polycaprolactone (PCL) and dimethylsulfone (DMSO2) composites can tailor the properties of scaffold materials, allowing their use in bone tissue engineering. With an increase in DMSO2 content, the modulus of the material increases but not the yield strength. In order to increase yield strength, a binder was added. However, the optimization of the content and the mixing process of the binder were not optimized in the previous studies. In this study, gamma-methacryloxypropyltrimethoxysilane (A-174) was used as a binder to increase the strength of a composite. Four different mixing processes were employed based on the binder mixing sequence. The binders with content of 0, 0.4, 0.5, 0.7, and 1.5 phr were employed. The yield strengths of composites were investigated in terms of the binder mixing sequence and binder content. When the binder and DMSO2 particle fillers were premixed in the PCL matrix consisting of a DMSO2 filler and an A-174 binder system, the filler surface was coated smoothly and uniformly, and less agglomeration occurred. The yield strength of the composites with the appropriate mixing sequence was 36.71% higher than that of the specimen without a binder, which was attributed to the improved adhesion between the matrix and fillers. Upon increasing the binder content, elongation and tearing of the matrix surface were observed in the cross-sections after yield tests; however, the weakening of mechanical anchoring was caused by excessive binder content, and filler debonding was observed on the surface. Because of the use of the A-174 silane binder at a concentration of 0.5 phr and the premixing of the binder and filler, the highest performance in terms of strength improvement of a PCL-20 wt % DMSO2 composite was achieved.

Durability, permeability, and mechanical performance of sprayed UHPC, as an attribute of fibre content and geometric stability

Sprayed concrete relies on the presence of an accelerator to set rapidly in place and achieve adequate geometric stability. This significantly reduces its strength, workability, and limits its application to specialised projects whereby the technical advantages of spraying outweigh the limitations rendering it more suitable over conventional placing methods. This study proposes the development of a novel sprayed ultra-high-performance concrete (SUHPC), suited for the application of complex shaped structures, utilising high glass fibre content and thin section requirements to achieve geometric stability. The study assesses the effects of fibre content on the mechanical, permeability, and durability performance of the developed SUHPC, and provides an assessment of its feasibility for spraying complex shaped free form architectural structures. The study found that incorporating high fibre contents in excess of 2 vol% allowed the mix to maintain geometric stability, while attaining ultra-high compressive strengths of up to 144 MPa. Meanwhile the durability and permeability performance remained above the typical threshold for typical UHPC. This study allows the revitalisation of UHPC for sprayed applications, incorporating an all-in-one architectural and structural design solution.

Pengaruh Lama Fermentasi Menggunakan Mikroba Ghalkoff terhadap Perubahan Konsentrasi Kandungan Kafein Kopi Robusta Organik Kabupaten Lampung Barat

Coffee is a beverage ingredient not only famous in Indonesia but also famous throughout the world. Caffeine is the most important compound found in coffee, caffeine functions as an element of taste and aroma in coffee beans. Excessive acid and caffeine content in coffee can have an impact on health. This study aims to determine the effect of fermentation time using microbial Ghalkoff on changes in concentration of caffeine, protein and acidity content in organic robusta coffee without reducing the taste of coffee. This research was conducted from July to August 2018 at PT. Ghaly Roelies Indonesia, Kecamatan Kemiling, Bandar Lampung. This study uses a laboratory and Kruskal-Wallis test Non-parametric statistical test based on questionnaire test on the level of preference. The results showed the effect of changes in the concentration of caffeine, protein and acidity levels in organic robusta coffee with control of the initial data resulting in a decrease in the concentration of caffeine by 27%. While the results of the N-Rank organoleptic test with Kruskal-WallisTest showed that administering long-acting organic coffee fermentation using microbial ghalkoff can increase the preference for coffee flavor, aroma and color. Keywords: Caffeine, Fermentation, Kruskal-Wallis Test, Organic Robusta Coffee.

Effects of film mulching and soil wetted percentage of drip irrigation on soil hydrothermal conditions and sweet potato growth

Sweet potato is widely cultivated in China because of its drought tolerance, low planting cost and richness in various nutrients, such as crude protein, carbohydrates, and cellulose. Field experiments were conducted at the Special Potato Experimental Station, China Agricultural University, Rizhao City, Shandong Province, China, in 2020 and 2021 to investigate the effects of film mulching and soil wetted percentage on soil hydrothermal conditions and sweet potato growth. Three mulching treatments (black plastic mulching, BM; transparent plastic mulching, TM; and no mulching, NM) were applied on the raised bed surfaces after drip tape laying and three soil wetted percentages (0 %, P0; 30 %, P1; and 60 %, P2) were conducted during irrigation. Soil temperature and water content, vine length, and stem thickness were monitored at each growth stage and tuber grade, yield, and quality were measured at harvest. The results indicated that mulching had significant effects on soil temperature, sweet potato growth, grading, water use efficiency, and yield. The BM and TM treatments significantly increased the soil temperature at the 0–5 cm soil depth up to 4.4 and 3.7 °C during the seedling stage, respectively. Three hours after the irrigation, the soil temperature at the 5 cm soil depth decreased by 6.4, 7.3, and 6.7 °C in the NM, TM and BM treatments in 2021, respectively. The BM treatment significantly increased the tuber number and weight of the sweet potato (tuber weight > 200 g) by 63.4 % and 73.7 %, respectively, and the TM treatment by 63.5 % and 70.7 %, respectively. The sweet potato yield with the film mulching treatments was 10.8–20.8 % and 44.4–59 % greater than that without the mulching in 2020 and 2021, respectively. The film mulching significantly increased the water use efficiency and decreased the excess water content during the rainy season. Film mulching was more important for the growth of the sweet potatoes than the irrigation in this study.

Изучение биологических и функциональных свойств микроорганизмов с высокой устойчивостью к марганцу (II)

The issue of water treatment of the central water supply, as well as wastewater, from excessive content of heavy metals (HMs) remains relevant at the present time. The presence of heavy metals, even in trace amounts, has a negative impact not only on the environment, but also on all human organic systems. At the moment, iron and manganese are among the main pollutants entering the human body via drinking water. Studies were carried out on the biological and functional properties of microorganisms isolated from highly magnetic soil, which previously demonstrated high resistance to manganese (II). Microbial strains with maximum resistance to Mn (II) were identified as: Bacillus simplex 55.2, B. simplex 13.2 and Listeria murrayi 13.4. The growth dynamics of B. simplex 55.2 and B. megaterium 69.5 was studied under conditions of periodic cultivation in a liquid medium containing 2 mmol/L Mn (II). It was shown that after 7 day’s cultivation, the weight of the biomass of B. megaterium 69.5 increased by 5.5 times, B. simplex 55.2 increased by 3.7 times relative to the values after 1 day cultivation, the optical density of the culture medium B. megaterium 69.5 increased 4 times, B. simplex 55.2 increased 2 times compared with the initial sowing dose. The specific growth rate of B. megaterium 69.5 after 7 days cultivation was higher than that of B. simplex 55.2 by about 2 times, and the degree of removal of Mn (II) from the aquatic environment was less. B. simplex 55.2 reduced the content of Mn (II) by 66%, B. megaterium 69.5 reduced by 50%. It was established that B. megaterium 69.5, B. simplex 55.2, B. simplex 13.2 and L. murrayi 13.4 are able to grow in conditions of high alkalinity and mineralization of the medium (pH 7–10; 10% NaCl). Taking into account that these microorganisms are able to remove high concentrations of Mn (II) from the aquatic environment, they are promising for their use in water treatment biotechnology.

Managing occupational impulsive noise from explosive depth hardening operations

The assessment and identification of measures to eliminate or reduce risks from occupational exposure to impulsive noise for the protection of hearing of employees in industry is an important yet comparatively neglected technical area. The aim of this work is to examine the current best practice to assess auditory hazards associated with impulsive blast noise generated by an infrastructure test process at a UK-based test site. A summary of the literature is presented on the measurement methodologies, hearing conservation and relevant guidance for the selection of hearing protection within the context of near-field impulsive noise. The current UK best practice recommends the adapted HML method from Defence Standard 0027:2015, using a C-peak measurement of exposure to compare with the national regulations. On-site measurements of personnel exposure were made at the DNV Spadeadam Testing and Research Site (STaR), of an industrial process known as Explosive Depth Hardening. Analyses of the trials data show that the C-peak personnel exposures resulted in acceptable levels below the 140 dBCpk limit within the national regulations when using the prescribed hearing protection, according to the adapted HML method. Waveforms recorded of repeated charge sizes were uncorrelated and additional signal artefacts were present. It is concluded that the adapted HML assessment is unclear on how excessive low-frequency content and multiple pressure peaks are accounted for in the assessment of hearing protector performance. The implication of this work is that further research is required to improve current best practice to quantify the uncertainties introduced by the additional characteristics found within real impulsive noise exposures.

Formation of SiV centers by doping in bottom-up grown HPHT nanodiamonds and its implication for optical nanosensig

We investigate doping and formation of luminescent point defects in nanodiamond at high pressures and high temperatures (HPHT) in fluorine-containing hydrocarbon growth systems with an excessive content of dopant organosilicon component. It is shown experimentally that the average concentration of silicon-vacancy centers (SiV-) tends to increase proportionally to the diameter of the nanocrystals. Respectively, the local concentration of the dopant in a crystal linearly increases with the distance from the crystal center. This phenomenon is explained by competition between growth of a perfect crystal and doping. The kinetics of the crystal growth are determined by the diffusion of carbon containing precursors to the surface of the crystal and the doping takes place at a very high concentration of the dopant in the growth mixture and that is defined by the rate of the chemical reaction on the crystal surface. Electrodynamic effects in the nanocrystals affecting the observed intensity of the photoluminescence are also considered. Although these results are obtained using important for applications SiV- photo luminescent centers, they have much wider implications.

Roles of waste carbon fibers on the efficiency of multiple induction heating healing behavior in asphalt mixture for sustainable infrastructure

This study systematically investigated the potential of waste carbon fibers (WCFs) as a sustainable solution in enhancing the multiple induction heating healing of asphalt mixture, thereby tackling two major concerns: the environmental impact of WCFs and the durability of asphalt pavement. Firstly, four groups of asphalt binder samples with different WCFs contents were prepared. The viscosity and workability of WCFs modified asphalt binder were analyzed. Next, asphalt mixture containing 2% steel fibers was prepared at the optimal WCFs content, while control groups without WCFs were prepared with 2% and 4% steel fibers content. A comprehensive study was conducted on the induction heating rate, effective heating depth and surface temperature cooling rules of the asphalt mixture. Finally, by conducting multiple "fracture-healing" tests, the influence of WCFs on the healing efficiency of asphalt mixture was analyzed. The results revealed that WCFs increased the viscosity of the virgin asphalt, but excessive WCFs content hindered the workability. The optimal WCFs content was determined to be 1% (by weight of asphalt binder). WCFs enhanced the thermal conductivity of the asphalt mixture, accelerating heating and improving vertical heat transfer while reducing surface temperature decline. During multiple "fracture -healing" processes, the inclusion of WCFs enhanced the mechanical strength of the asphalt mixture, improved its healing efficiency, and increased the number of healings. Even after five cycles, the specimen with the most damage still showed a fracture energy recovery rate (FERR) of over 30%. In conclusion, WCFs significantly enhanced the multiple induction heating healing efficiency of the asphalt mixture.

Impact of GNP content on cure behaviors and diverse properties of epoxy composites modified with graphene nanoplatelets: A comprehensive study

Nanocomposites modified with graphene nanoplatelet (GNP) have garnered significant attention and widespread application across various domains due to their substantial property enhancements. Nevertheless, excessive GNP incorporation not only leads to agglomeration within the polymer matrix but also degrades the base polymer's performance. Consequently, an investigation into the impact of GNP content on nanocomposite performance holds considerable significance. This study involves the dispersion of GNP with varying weight percentages into epoxy resin (EP) via ultrasonic dispersion to synthesize nanocomposites. The isothermal viscose-time properties were investigated to clarify the effect of the GNP on the curing speed and to suggest a suitable operating time for industrial production. Differential scanning calorimetry (DSC) was employed to investigate the curing kinetics so as to calculate the kinetic parameters and guide the curing process in practical industrial applications. In addition, mechanical properties and microstructure morphologies were analyzed by the direct tensile tests and scanning electron microscope (SEM) tests. Results showed that the addition of GNP in appropriate amounts is effective in promoting the curing reaction and improving the mechanical behavior. Specifically, GNP content was positively correlated with the increase of viscosity during the curing of the system. The EP@GNP-2 blend with 2 wt% GNP had the most significant effect on reducing the apparent activation energy, indicating that too much GNP may have an inhibitory effect on the curing reaction. The curing process parameters, including the gelling temperature (Tgel), curing temperature (Tcure) and post-treatment temperature (Ttreat) were calculated through the T-β extrapolation method. The elastic modulus of EP@GNP-1, EP@GNP-2 and EP@GNP-3 specimens increased by about 5%, 18% and 25%, respectively. However, the elongation at break showed a trend of increasing and then decreasing with the increase of GNP content. SEM tests show that excessive GNP content will attribute to the formation of a long barrier-like structure in the epoxy matrix to block the cross-linking of epoxy molecules on both sides, and the GNP agglomerates become stress concentration points and aggravate the brittleness of the nanocomposite. Furthermore, although a clear negative correlation between GNP content and thermal stability was revealed, the incorporation of GNP significantly enhances electrical conductivity. The results suggest that a reasonable GNP content is necessary, and a GNP content of 2 wt% is a recommended value for improving mechanics and curing efficiency.

Iraj Mirzā: Women and Their Representation in His Poetry

Abstract Iraj Mirzā has a reputation for excessive sexual content in his poetic oeuvre. His “forbidden literature,” so to speak, and to quote Paul Sprachman, has suffered unjustly from charges of frivolity, and while vanity and profanity do indeed feature prominently, these allegations disregard the artistic high-mindedness that is ever-present in the prince’s extensive canon. Recent scholarship has attempted to rehabilitate his reputation by highlighting the formalistic aspects of his poetry as well as by emphasizing the striking intricacies of his particular poetic perspective. In this article, I will delineate Iraj’s line of poetic maturity—especially when interlaced with thoroughgoing thoughts of Constitutional Revolution—and will discuss how, juxtaposing the stylistic decorum of classical Persian poetry with interlocution and colloquialism, he could impact the upcoming movement of new poetry (she‘r-e no) in Iran. More emphatically, I will illuminate how Iraj Mirza’s attitude toward women is self-contradictory—though in some places he seems sympathetic toward women, criticizing the restrictions placed on them in Qajar Iran, he ultimately betrays them by degrading them to the status of sex objects as in ‘Ārefnāmeh, where he depicts the veil as an obstacle to women’s and the country’s progress and he contaminates women’s chastity by justifying his (character’s) raping. Iraj’s boldness in addressing female genitalia and sexual intercourse pushed the boundaries of literature in transitional Qajar era; however, seen from a feminist perspective, his poetry equates the Persian literary woman to the fictionalized demimonde who wished to be sexually abused.

Water content significantly influences post-cryopreservation survival of air-desiccated oil palm (Elaeis guineensis Jacq.) zygotic embryos: A thermal and ultrastructural study

The present study outlines the influence of free water content in oil palm (Elaeis guineensis Jacq.) zygotic embryos after desiccation on survival post-cryopreservation. Aseptically isolated zygotic embryos were analysed for water content and resurgence ability after air-desiccation and freezing (in liquid nitrogen). The results indicated that the desiccated zygotic embryos with water content of below 0.24 and above 0.16 g H2O /g dry weight (dw) exhibited survival after freezing. The survival was maximum (80%) when the desiccated zygotic embryos contained 0.16 g H2O /g dw of water content. This optimal water content not only helped oil palm zygotic embryos to sustain their cellular integrity but also assisted to retain their regeneration potential following cryopreservation. On the contrary, the zygotic embryos with water content above 0.24 g H2O /g dw or below 0.16 g H2O /g dw lost their viability as well as their cellular integrity attributable to either excess water content or excessive loss of water, after desiccation and successive freezing. Differential scanning calorimetric analysis revealed characteristic sharp peak for zygotic embryos with high water content and reduced peaks with successively lower water content. Scanning electron microscopic and transmission electron micrographic studies also confirmed that there was no noteworthy distinction in morphology of epidermal layer and cellular integrity between zygotic embryos with different water content before and after desiccation as well as their successive freezing. The parallel trend was reflected in their revival also.

Effects of dietary eicosapentaenoic acid on the growth performance, fatty acid profile, immunity and heat tolerance of juvenile abalone Haliotis discus hannai Ino

A 93-day growth trial was performed to evaluate the influences of graded dietary EPA levels (0.03% (control group), 0.24%, 0.63%, 1.07%, 1.72% and 2.25%) on the growth performance, immunity and heat tolerance of juvenile abalone Haliotis discus hannai with a mean initial weight of 4.15 ± 0.18 g. After the feeding trial, the findings found that the highest weight gain rate (WGR) belonged to the groups fed with 0.63% ∼ 1.72% of dietary EPA (P < 0.05). The lowest feed conversion ratio was distinguished in the groups with 0.63% ∼ 1.07% of dietary EPA (P < 0.05). Also, EPA supplementation in abalone feed increased the content of crude lipid in the soft body and the activity of lipase in the intestine (P < 0.05). The total antioxidative capacity increased when dietary EPA levels rose from 0.03% to 1.07%, and then decreased (P < 0.05). Furthermore, compared to the control group, the 0.24% and 0.24% ∼ 0.63% of dietary EPA significantly down-regulated the mRNA levels of IκB kinase and kelch-like ECH-associated protein 1, respectively (P < 0.05). However, nuclear factor-κB and interleukin 1 receptor-associated kinase 4 genes expression in the digestive gland were significantly up-regulated by the use of 1.72% and 2.25% of EPA in diet (P < 0.05). The mRNA levels of tumor necrosis factor α and interleukin 16 were significantly up-regulated by the 2.25% of dietary EPA (P < 0.05). The 1.72% of dietary EPA significantly increased the falling rate of abalone after the heat stress compared with the control (P < 0.05). In conclusion, the optimal dietary EPA requirement of juvenile abalone was determined as 1.36% based on quadratic regression analysis against WGR. Moderate dietary EPA content (0.63% ∼ 1.07%) improved the immunity and heat resistance of abalone. Excessive dietary EPA content (1.72% ∼ 2.25%) decreased the growth, meanwhile, increasing the oxidative stress, inflammation and susceptibility of abalone to heat stress.

Soil Bulk Density and Matric Potential Regulate Soil CO2 Emissions by Altering Pore Characteristics and Water Content

Soil pore structure and soil water content are critical regulators of microbial activity and associated carbon dioxide (CO2) emissions. This study evaluated the impacts of soil bulk density and matric potential on carbon dioxide (CO2) emissions through modifications of total porosity, air-filled porosity, water retention, and gas diffusivity. Soil samples were manipulated into four bulk densities (1.0, 1.1, 1.2, and 1.3 Mg m−3) and ten matric potential levels (−1, −2, −3, −4, −5, −6, −7, −8, −9, and −10 kPa) in controlled soil cores. The results showed that lower bulk densities enhanced while higher densities suppressed CO2 emissions. Similarly, wetter matric potentials decreased fluxes, but emission increased with drying. Correlation and regression analyses revealed that total porosity (r = 0.28), and gravimetric water content (r = 0.29) were strongly positively related to CO2 emissions. In contrast, soil bulk density (r= −0.22) and matric potential (r= −0.30) were negatively correlated with emissions. The results highlight that compaction and excessive water content restrict microbial respiration and gas diffusion, reducing CO2 emissions. Proper management of soil structure and water content is therefore essential to support soil ecological functions and associated ecosystem services.

ANN approach to evaluate the effects of supplementary cementitious materials on the compressive strength of recycled aggregate concrete

The growing awareness of environmental issues has triggered significant research into the impacts generated on the environment during concrete production. To improve sustainability in this process, ordinary Portland cement (OPC) and natural aggregates (NA) have been replaced by recycled concrete aggregates (RCAs) and supplementary cementitious materials (SCMs) to reduce the negative issues to the environment. However, the use of SCMs can be challenging due to their complex chemical composition, and RCAs are often of inferior quality compared to NAs, leading to reduced concrete strength. To address these issues, an artificial neural networks (ANN) model has been used for calculating the compressive strength of concrete mixes that oodórate SCMs and RCAs. To train the model, 1181 concrete mixtures from 116 sources were included, considering parameters such as hydraulic reactivity, silica, and alumina modulus. In this research was found that the ANN model is an effective instrument to predict concrete strength even with the use of SCMs and RCAs. The analysis of input variables using the Connection Weight Approach (CWA) concludes that silica fume is the external material that, when mixed with RCA, significantly improves the resistance of concrete, followed by the reactivity modulus of cementitious materials, cement content, silica modulus, fine NA content, and coarse NA dosage. Conversely, excessive ood dosage, high ood/cement ratio, and excessive RCA content (fine and coarse) negatively affect concrete strength.

A new approach to improving the water resistance of MOC-solidified sludge using [formula omitted] ions

With the growing sustainability concerns and awareness of environmental conservation, utilizing magnesium-based cement in construction has garnered considerable attention in recent years. In this work, a novel and sustainable approach to treating sludge has been developed by incorporating NaHCO3 to enhance the properties of MOC (Magnesium Oxychloride Cement)-solidified sludge. Different properties were determined through various experimental techniques, such as unconfined compressive strength (UCS), durability, scanning electron microscopy (SEM), X-ray diffraction (XRD) tests, and mercury intrusion porosimetry (MIP) to assess the impact of NaHCO3 content, curing age, and other factors on the strength, water resistance, microstructure, and reaction products of MOC-solidified sludge. The results indicate that adding NaHCO3 significantly enhanced the compressive strength and water resistance of MOC-solidified sludge, with an optimum NaHCO3 content of 50%. However, excessive NaHCO3 content led to a reduced MOC content, as evidenced by a strength loss rate of approximately 50% when NaHCO3 content reached 200%. Adding NaHCO3 also produces hydrated magnesium carbonates in solidified sludge in addition to Phase 5 and Brucite (Mg(OH)2). The expansion and cementation properties of these reaction products effectively filled the pores of the samples, facilitating the bonding of soil particles, establishing a stable spatial network structure, and improving the resulting strength of MOC-solidified sludge.

RANCANG BANGUN DESALINASI SURYA TIPE SINGLE BASIN DOUBLE SLOPE DI SELAT PANJANG KOTA-RIAU

People in coastal areas must buy or use rainwater to get clean water, but the availability of clean water itself still depends on the availability of nature where when the dry season comes it is very difficult to get clean water. The solution to this problem is to utilize seawater through a seawater purification process (desalination) by removing excess salt content in the water by utilizing solar energy. The aims of this study are to design, manufacture, and test solar desalination with a single basin double slope type with the addition of an internal reflector and a wick in the form of a sponge. Where the test was carried out in Selat Panjang Kota, Meranti Islands Regency, Riau Province, Indonesia (1° North Latitude and 102.70° East Longitude). This study resulted in the highest efficiency found in the test with a sponge pore dimension of 0.20 mm compared to a sponge pore dimension of 0.35 mm and 0.50 mm. With the average intensity of solar radiation on that day of 733,079 W/m2, the desalination water produced was 3,380 kg and the efficiency was 27.05%. The quality of the desalinated water shows that all test parameters have values below the drinking water standard, which is given by the Minister of Health Regulation NUMBER 492/MENKES/PER/IV/2010. This indicates that desalinated water is suitable for drinking as well.

Self-Purifying Primary Solvation Sheath Enables Stable Electrode-Electrolyte Interfaces for Nickel-Rich Cathodes.

Herein, we optimize the primary solvation sheath to investigate the fundamental correlation between battery performance and electrode-electrolyte interfacial properties through electrolyte solvation chemistry. Experimental and theoretical analyses reveal that the primary solvation sheath with a self-purifying feature can "positively" scavenge both the HF and PF5 (hydrolysis of ion-paired LiPF6), stabilize the PF6 anion-derived electrode-electrolyte interfaces, and thus boost the cycling performances. Being attributed with these superiorities, the NCM811//Li Li metal battery (LMB) with the electrolyte containing the optimized solvation sheath delivers 99.9% capacity retention at 2.5 C after 250 cycles. To circumvent the impact of excess Li content of Li metal on the performance of NCM811 cathode, the as-fabricated NCM811//graphite Li ion battery (LIB) also delivers a high-capacity retention of 90.1% from the 5th to the 100th cycle at 1 C. This work sheds light on the strong ability of the primary solvation sheath to regulate cathode interfacial properties.

High damage-resistance and fracture toughness of transparent Nb-doped barium aluminoborate glass ceramics

Glass-ceramics offer the opportunity to address the main disadvantage of oxide glasses, namely low fracture toughness. The presence of crystals can improve the fracture toughness (crack growth resistance), but the crack initiation resistance will typically be deteriorated due to the induced residual stresses. Excessive crystal content and large crystal size can also lead to a loss of transparency. In this work, we report a Nb-doped barium aluminoborate glass-ceramic, for which both the crack initiation resistance (CR) and fracture toughness (KIc) get improved upon heat treatment, while still maintaining some transparency. Relying on combined structural and mechanical characterizations, we demonstrate that the coordination numbers of B and Al in the glass phase decrease upon heat treatment, which is beneficial to energy dissipation under mechanical stress to improve CR. Furthermore, the formed piezoelectric crystal phase BaNb2O6 also helps to improve both CR and KIc, likely by converting the stress-induced mechanical energy into electric energy. Meanwhile, the increase in crystallinity and crystal size after heat treatment also leads to higher KIc of the glass-ceramics. These findings thus help address the difficult problem of simultaneously improving the resistances to crack initiation and growth, which will facilitate the future design of transparent, yet highly damage-resistant and damage-tolerant glass ceramics.

Polymer-Functionalized Laser-Induced Graphene Electrochemical Sensor for Selective and Sensitive Detection of Fluoride Ions in Real Water Samples

Fluorosis is a worldwide public health problem induced by excess fluoride content in soft and hard tissues in body, necessitating the development of fluoride sensors. This work demonstrated a flexible, cost-effective, quantitative, and selective fluoride (F-) sensor for fluoride ion detection in water samples. The miniaturized sensor was realized on a polyimide sheet by laser ablation, forming a three-electrode system with laser-induced graphene (LIG). The 3-electrode system comprises a working electrode with chemically modified LIG with electropolymerized polymer, LIG coated with Ag/AgCl conductive ink as reference, and a bare LIG as a counter electrode. The surface chemistry and morphology of the sensor were analyzed by physicochemical characterization. The electrocatalytic activity of F <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> ions on the electrode surface was studied using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The F <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> ions concentration of the proposed sensor was found to be in the linear range from 5 μM to 130 μM. The limit of detection (LoD) and limit of quantification (LoQ) were obtained as 2.218 μM (0.093 ppm), 6.723 μM (0.282 ppm) which are much lesser than the permissible safe limit. The sensitivity was found to be 0.0168 μA/μM∙cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The impact of other parameters, like scan rate, pH influence, interference, and reproducibility, were analyzed and to comprehend the sensor usability in real-time, a lake water sample was also tested and analyzed. The proposed sensor was found to have consistent repeatability and a good recovery rate. Owing to its flexibility, the sensor can further be miniaturized by integrating it into a microfluidic platform.

An Alternative Thinking in Tumor Therapeutics: Living Yeast Armored with Silicate.

A hybrid platform, constructed via the surface "armoring" of living yeasts by a manganese silicate compound (MS@Yeast), is investigated for combinational cancer treatment. The intrinsic characteristics of living yeasts, in both acidophilic and anaerobic conditions, empower the hybrid platform with activated selected colonization in tumors. While silicate particles are delivered in a targeting manner, yeast fermentation occurs at the cancerous region, inducing both alcohol and CO2. The excessive content of alcohol causes the hemangiectasis of tumor tissue, facilitating the penetration of therapeutics into central tumors and subsequent endocytosis. The catalytic Mn2+ ions, released from silicate particles, react with CO2 to induce forceful oxidative stress in tumor cells, ablating the primary tumors. More interestingly, the debris of sacrificed tumor cells and yeasts triggers considerable antitumor immune responses, rejecting both rechallenged and metastatic tumors. The integration of biologically active microorganisms and functional materials, illustrated in this study, provides distinctive perspectives in the exploration of potential therapeutics for tackling cancer.